1. Field
Example embodiments of the following description relate to a method and apparatus for processing a virtual world, and more particularly, to a method and apparatus for controlling a facial expression of an avatar in the virtual world using a facial expression of a user in a real world.
2. Description of the Related Art
Currently, interest in experience-type games has been increasing. The MICROSOFT CORPORATION introduced “Project Natal” at the “E3 2009” Press Conference. “Project Natal” may provide a user body motion capturing function, a facial recognition function, and a voice recognition function by combining MICROSOFT's XBOX 360 game console with a separate sensor device consisting of a depth/color camera and a microphone array, thereby enabling a user to interact with a virtual world without needing a dedicated controller. Also, the SONY CORPORATION introduced “Wand” which is an experience-type game motion controller. “Wand” enables a user to interact with a virtual world by using a motion trajectory of a controller and applying, to the PlayStation 3 game console, location/direction sensing technology, which is obtained by combining a color camera, a marker, and an ultrasonic sensor.
With recent developments of technologies enabling interactions between a real world and a virtual world, technology related to an avatar in the virtual world, the avatar representing a user in the real world, is being actively researched and developed. For example, technology that processes a certain gesture made by the user and enables an avatar in the virtual world to make the same gesture as the user is under development.
Further, a human face may function as a form of communication, which conveys a host of information through a facial expression. In the field of virtual reality, an agent of the user, that is, the avatar, is the subject of an activity. Therefore, the proper modeling of the agent is an important matter. Furthermore, since the face is an object capable of conveying the most amount of information, technology achieving a more realistic level of modeling and animation is to be applied.
In the section of moving picture experts group, phase 4 (MPEG-4) and synthetic natural hybrid coding (SNHC), integrated coding of a natural image and a synthetic image based on interaction is standardized. The first standard plan suggests a face description parameter (FDP) which describes a face through coding of a face object used in the virtual world, and a facial animation parameter (FAP) which describes motions.
However, the FAP of MPEG-4 defines only motions of respective facial parts. Therefore, to achieve realistic animation of a facial expression change and lip synchronization, an operation system functioning as muscles of a real human face needs to be provided in a modeled face object.